Martha Jones (played by Freema Agyeman) will return to the Doctor later in the upcoming 4th Series, and so will an even older acquaintance of the Doctor’s – the Sontarans. First seen with the 1973 story “The Time Warrior”, the bulbous warriors will have to face the Doctor, Jones, and Donna Noble (Catherine Tate, having taking the permanent companion role from Agyeman). Playing the head of the Sontarans is Christopher Ryan (Young Ones).